Patent Document 1 discloses a control device for an internal combustion engine including: a variable intake valve timing mechanism; a variable exhaust valve timing mechanism; a lock mechanism configured to lock the intake valve timing at a point; a crank angle sensor configured to output a crank angle signal; an intake cam sensor configured to output an intake cam signal; and an exhaust cam sensor configured to output an exhaust cam signal. In the disclosure of Patent Document 1, when an abnormality occurs in the crank angle sensor, the control device controls the operation of the variable intake valve timing mechanism based on the exhaust cam signal to enable the lock feature of the lock mechanism and controls the engine based on an estimated crank angle that is calculated based on the intake cam signal.